Elemental sulfur is known to be moldable, but the low tensile strength and brittleness of the resultant product makes it unsuitable for many purposes. Modified or plasticized sulfur has been used in building construction, as flooring surfaces, for roadway paving and roadway marking in view of its excellent adhesion to substrates and resistance to abrasion and corrosion. For example, sulfur concrete has been used to fabricate corrosion-resistant tanks and as flooring surfaces in highly corrosive areas. The sulfur concrete can be made by adding 5% by weight of a chemical modifying agent to molten sulfur at 130.degree. C. The modified sulfur is then added to aggregate which has been heated to 155.degree. C. and mixed thoroughly and then cast. Usually the composition of the sulfur concrete is 15%-25% modified sulfur and 75%-85% aggregate by weight. Various materials such as crushed rock, sand, colorants, mica, glass beads, glass fibers and asbestos have been used with chemically-modified sulfur.
Chemically-modified sulfur mixtures are disclosed in various U.S. Patents. For example, U.S. Pat. No. 3,306,000 describes a method of bonding building blocks with a plasticized sulfur composition consisting essentially of sulfur, a polysulfide polymer plasticizer and glass fibers. U.S. Pat. No. 3,316,115 describes marking compositions of sulfur and a polysulfide polymer plasticizer, which may contain additionally glass beads, sand, pigment, glass fibers and the like. U.S. Pat. No. 3,459,717 describes sulfur-based plastic compositions containing sulfur, a monoethylenically unsaturated hydrocarbon and diester of dithiophosphoric acid which may also contain glass fiber, yellow pigment, glass beads and the like. U.S. Pat. No. 4,233,082 describes plasticized sulfur coating compositions which contain elemental sulfur and aliphatic linear polysulfides and an aromatic polymeric polysulfide and an inorganic filler selected from mica and asbestos. While the above described sulfur composites are satisfactory for application to substrates, there is a need for much stronger sulfur composite, free of hazardous asbestos, for the fabrication of structures such as pipes, fittings, tanks and the like.